Treadle operated centering machine



July 28, 1931. J. J. THACHER TREADLE OPERATED CENTERING MACHINE 4 Sheets-Sheet 1 Filed May 3, 1927 HINVENTOB I 87 W -ATTOR/VEY J. J. THACHER LSWAIQ TREADLHOPE RATED CENTERING MACHINE! 7 filed May 3, 1927 4 Sheds-Sheet 2 July-28, 1931. J. J. TI- IACHER 1,316,410

TREADLE OPERATED CENTERING MACHINE Filed Ma? '5, 1927' 4 Sheets-Sheet s IN VEN TUB A TTORNEY T y 1 i A HACHER 3,81%4162 TREADLETIOPERATED CE'NTERING MACHINE Fileci May z, 1927 lfiheets-Sheet 4 Patented July 28,

UNITED STATES PATENT OFFICE JOHN J. a r-manna, orwE'THnRsFrELn, coivrrnorrron r, ASSIGNOR To PRATT a? warm:

NEY COMPANY, on NEW YOBE-., n1.

TREAD E ornna'rnn onn rnnirne' MACHINE Application filed May 3,

This invention relates to Centering machines and particularly to one adapted to simultaneously centerthe opposite ends of a blank held against rotation during the cen- V I teringoperation.

Another object of the present invention is to provide an improved manually operated advancing means for the spindles carrying the centerlng drills so that movement in a vertical plane of a hand lever will simultaneously advance the drill spindles horizontally toward the blank to center the opposite ends of the work blank; Y

"A still further object of the present inven l ,tion is to provide resilient means to limit the force with which each drill spindle is advanced toward the work blank when the oper ator actuates the hand lever.

With these and .other 0b ects 1n view, my invention consists in the features of construction' andv operation set forth in the following" specification and illustrated in panying drawings.

In the accompanying the accomdrawings annexed hereto and forming a part of this specification, I have shown my invention embodied in a treadle' operated machine adapted to simultaneously center opposite ends of a work blank, but it will be understood that the inr i vention can be otherwise embodied and that in Fig; 1. V

Fig. 3 is a side elevation taken substantially upon the. line 33 of Fig. 2. i i

Fig. 3 is adetail sect'onal iew of a part of the work supporting means taken on line aaofFig.3.' H V Fig. I is a longitudinal sectional view in elevation of the drill head forming part of the present invention, and

) Fig. 5 isan end elevation of the mechanism Fig. 2 is aplan view of the machine shown,

1927., Serial in. 188,554,

shownin Fig. 4: partly brokenaway tomore clearly showits construction. l

In the abovementioned drawingsIghave shown but one embodiment of the invention which is now deemed preferable, but f'itisto be understood that changes and modifications 'may bemade withinthe scope of the appendcd claim without departing from the spirit of the invention: I

, Briefly, and in its broadest aspect, my invention comprises the followingfp'rincipal parts: First,;a base; second, drill heads mounted in opposed relation upon opposite ends of the base and adapted to be moved along the base; third, sleeves within said head movable axially and in alignment with each other; fourth, rotatably mounted spin- 1 dles within the sleeves adapted to be rotated at relative high speed by motors mounted on the heads; fifth, manually operated means to simultaneously'force the sleeves and spindles toward the opposite ends of the work being centered withfa predetermined maximum pressure; sixth, work supporting members adapted to support'work blanks of different diameters in axial alignment with the drill spindles; seventh,-plungers forming parts of the work supporting members having V- shaped notches at their rear ends adapted to engage the-periphery of work blanks being centered; eighth, abutments movable toward and from the plungers and adapted to con tact with the opposite side of the work blank being centered; ninth, lever mechanism actuated by a footftreadle toadvance the abutments nto operative position; tenth, auxiliary plungersdisposcd parallelly to and'ad- 'jfiCQIlb the plungers having the V notches and adapted on their rearward end to engage surfaceson the abutments; and eleventh, flu d means within the cylinders for said plungers,

theratios of these plungers being such that work of any diameter may be properly cen-' tered when the abutments are advanced to engagethe work and the auxiliary plungers forcethe first plungers to firmly engage the periphery of the work.

Referring more in detail to the figures of the drawings, I providea base lO, preferably-f mounted upon suitable pedestals 11 and adapted to support drill spindle mounting tool heads 12 on the opposite ends of the base. As these heads 12 may be and preferably are similar, a description of one will suffice, it being understood, however, that the heads will be in opposed relation and will have their drill spindles 13 axially advanced toward the opposite ends of the work being centered by manually operable means in one of the heads. The drill supporting heads 12 comprise body members adapted to be adjustably clamped to appropriate ways 14 on the sup port or base 10, as by means of the strap 15 engaging under the ways 14. This strap 15, one of which is provided for each head, is adapted to be clamped and unclamped by a transversely mounted shaft 16 having an cecentric 17 thereon at its rear end. A hand lei-er 18 on the forward end of this shaft 16 provides convenient means for clamping or loosening this strap 15 and thus permits adjustment of the head 12 along the base 10 for different lengths of work blanks.

Vithin the body member of the heads 12 is a sleeve 20 adapted to be axially movable and which is provided with oblique rack teeth 21 on its lower side. By means of a spline or key 22 this sleeve 20 is prevented from rotating while permitted to move axially. In engagement with the rack teeth 21 are teeth helically disposed on a segmental gear 23 mounted upon a recessed member 24 slidable on a shaft 25 parallel to the sleeve 20 and preferably disposed directly below it and within the head 12. Oscillation of this segmental gear 23 and member 24 will therefore advance or retract the sleeve 20 axially, depending upon the direction of movement of the member 24. To effect this movement of the segmental gear 23 and member 24, a hand lever 26 is provided directly attached to the member 24 carrying the gear 23 so that movement vertically of the hand lever 26 will advance or retract the sleeve 20 horizontally.

' As the sleeves 20 in the two heads 12 must 23 is rotatably and slidably mounted upon the shaft 25 and is normally held toward one end of the shaft 25 by a spring 27 surrounding the shaft 25 and extending within a recess of the member 24. It will be seen from this construction that when increased pressure is placed upon the hand lever 26 during the cutting operation the recessed member 24 will move toward the right and compress the spring 27, thus preventing undue or excessive pressure to advance the sleeve 20 carrying the drill spindle 13.

Within the sleeve 20 is coaxially mounted the rotatable spindle 10 which is preferably supported at its opposite ends by suitable roller bearings 28 inserted in recesses within the sleeve 20. A gear 29 on the rear end oi the spindle 13 provides rotating means and a collet chuck 30 on the opposite end provides means for clamping a centering drill within the spindle 13. In order to rotate the spindle 13 at high speed a motor 31 is mounted on a bracket 32 secured to the head 12 and provided with an elongated pinion 33 on the motor armature shaft. This pinion 33 is adapted to engage the gear 29 on the spindle 13 in any axialposition of the sleeve 20 and spindle 13. a

In order to simultaneously actuate the sleeves 20 in the two opposed drill heads 12 toward the ends of the blank so that opposite ends of a work blank W may be simultaneously centered a second segmental gear is mounted on the recessed member 24 within each head 12. 1 This gear 35 meshes with rack teeth on a transversely extending rod 36 within the body member is also provided with rack teeth at its rear end. These latter rac:

sleeve 20 and drill spindle 13 in the opposite head 12 in the opposite direction through the rack and gear connections to the longitudinal shaft 38. The spindles therefore simultaneously move toward and away from their cutting or operative position. To one of the gears 37 on the longitudinally extended shaft 38 may be coupled a reach or connecting arm 39- extending to the plunger 40 of the lubricant pump 41. By this means when the spindles 13 are being fed forwardly into the work the pump plunger 40 will be moved downward to force lubricant to the cutting surfaces of the drill.

In order to properly and accurately support work blanks V of different diameters co axially with the drill spindles 13 and to permit blanks V of different diameters within the capacity of the machine to be properly centered without manual adjustments for their different mliameters, the following mechanism is provided. Upon suitable supports adjustably mounted upon the ways 14 of the base 10 are plungers 51 operating withincylinders 52 formed within the supports 50 and having a V-shaped notch preferably of in their rear ends. The work being centered or otherwise acted upon is adapted to engage the angular surfaces of work blanks WV. These supports 56 and parts mounted thereon are similar to each other so that but one will be described. Adjacent and extending parallel to the plunger 51 is an auxiliary plunger 53 with n a second cylinder 54 within the support 50 connected to the first cylinder by a. suitable passage 55.

, plunger.

iliary ilunger is exactly 'double that of This second or auxiliary plunger 53 has a rearward extending projection 56. The relative cross sectional areas of these two plungers 51 and 53 with notches of 60 formed in the plungers 51 is such that movement of the auxiliary plunger 53 will move the first plunger 51, which engages the work. exactly one-halfthe distance moved by the auxiliary In other words the area of the auxthe first cylinder 51; With different angles between the surfaces of the notches in the pluugers 51 it will be'understoodthat the ratios between the diametersof theplungers 51 and 53 will be varied accordingly. For

- claims directed to the work positioning device attention is called to my application. K Serial No. 310,117, filed October 3, 1928, a.

division of this application.

To engage the opposite side of the work blank W and to simultaneously engage the projection 56 on the auxiliary plunger 53 to 34; force that plunger to correspondingly ad- (ill vance. the first plunger 51, a member 58 is provided as shown clearly in Fig. 3. This able ways within the support toward and from the plungers 51 and 53. Upon movement forward of the member 58 it engages the work blank W and forces the blank W against the surfaces of the notch in the plunger 51. This supports the blank W at an elevation corresponding to that of the spindles 13.

Simultaneously forward movement of the member 58 causes it to engage the projection 56 on auxiliary plunger 53 and force'the plunger 51 rearwardlythrough the liquid within the cylinders 52 and 54. Thismovement of the plungers 51 and 53 and the member 58 continues until the blank W is firmly held between the surfaces of the notch in plunger 51 and the forward surface of the member 58. The relative movement of the plunger 51 and the member 58 is such that blanks W will be held upon the same axis regardless of their diameter. To initially adjust the plunger 51 so that the axis upon which blankslV areheld will coincide with the axis of the spindles 13, an adjustment of the plungers 51 and 53 is provided. This comprises a screw which may be screwed in or out to slightly vary the space within the inner ends of cylinders 52 and 54 and the passage 55. The effect of this adjustment is to slightly vary the lateral position of the plunger 51 and member 58 when a blank W is held between them. To initially. adjust member 58 is adaptedto be movedin suit-'v the plunger51- to the-correct height aneccentric sleeve 51* is inserted within the cylinder 52 closely surrounding the plunger 51. By rotating the sleeve 51 the elevation of the plunger 51 may be slightly varied, A clamping screw 57 is provided to tightly hold the sleeve 51 in adjusted position. To

hold the plungers 51 and 53 from rotation and from movement beyond limited positions, screwsv 5,9 are provided adapted to engagesplines formed within the plungers 51 and 53. f 5 f The mechanism for advancingthe member 58 toward and from its operative position isshownfully in Fig. 3. This comprises afoot treadle 62 adapted to be oscillated. about the axis of a shaft63. Preferably this shaft 63 is supported for rotation in a bracket 64 cured upon the rear surface of the base 10. For convenience the trcadle 62 may be adjusted along the shaft 63 between the projections on the bracket 64 supporting the shaft.

The shaft 63 has secured to it a lever 65 provided with gear teeth adapted to mesh with teeth on the lower end of a lever 66 mounted for pivotal movement about a stud 67 in the bracket 64. treadle 62 will oscillate the lever 66. The upper end of this lever 66, through a suitable short connecting link 68, is pivotally connected to an oscillating'member 69 adapted to oscillate with a shaft 70 mounted in the bracket .64. The shaft 70 is splined substan tially throughout its length and is provided with levers 71, one for each of the supports 50. Oscillation of the shaft 70 therefore oscillates the levers 71 which are attached through connecting rods72 to the member or block 58.

A spring 73 is interposed between the lever 71 and rod 72 permitting the lever 71 to be moved to a limited position with blanks W ofany diameter.

7 In their work clamping position the lever 66 and link 68 are in alignment, thus acting similar to the links of a toggle. Similarly the members 71 and 72 are in alignment when the member 58 is in its forward or work clamping position.

To return the treadle 62 and connected 7 V parts to its inoperative position, a spring 7;) 1s provided normally forcing the lever 65 to its outer position and the treadle to its upper position.

The supports 50 are adjustably secured to sleeve forming a support for said spindle and Movement therefore of the splined to said base whereby it is axially movable therein but restrained from rotation, means to axially move said sleeve comprising rack teeth formed on one side thereof, a helical gear mounted Within said head upon an axis parallel to said sleeve and engaging said rack teeth, said gear being resiliently forced axially in one direction Within said head and permitted to move axially in the opposite direction to a predetermined position When the pressure upon the sleeve exceeds a predetermined amount means to oscillate said gear in a plane normal to the axis of said sleeve, and means on said helical gear to actuate a sleeve and spindle disposed in another drill head.

In testimony whereof I hereto affix my signature.

JOHN J; THACHER. 

